Ultra-thin anatase TiO2nanosheets dominated with {001} facets: thickness-controlled synthesis, growth mechanism and water-splitting properties

Abstract

Ultra-thin anatase TiO₂ nanosheets with dominant {001} facets (∼82%) and controllable thickness (1.6–2.7 nm) were synthesized by using a modified one-pot hydrothermal route. As a morphology controlling agent, the concentration of hydrofluoric acid has a significant impact on the thickness of the as-synthesized TiO₂ nanosheets. In addition, according to the XRD patterns and TEM images of the products on different reaction stages, the growth process of TiO₂ nanosheets was clarified for the first time. We further measured the efficiency for H₂ evolution of the ultra-thin anatase TiO₂ nanosheets loaded with 1 wt% Pt from photochemical reduction of water in the presence of methanol as a scavenger. The TiO₂ nanosheets exhibited a H₂ evolution rate as high as 7381 μmol h⁻¹ g⁻¹ under UV-vis light irradiation, attributing to their exposed reactive {001} facets and high crystallinity.